A rotatably supported plate of the abovementioned type is described for example in GERMAN OS No. 2,324,078. In this known construction, the sole plate consists of a base plate which is on the side of the ski and a sole plate which is on the side of the boot. The space between the plates is protected by an expandable sleeve against external influences. The two plates are connected by a bearing, the vertical axis of rotation of which extends through the axis of the shin and the horizontal axis of rotation of which lies transversely with respect to the longitudinal direction of the ski in a plane in the vertical axis. The vertical support is for the friction reduction constructed as a ball bearing, while the horizontal support consists in the form of a friction bearing of bolts and tetrapolyethylene-fluoride sleeves.
The just-described embodiment of the known device permits one to recognize at the same time the first disadvantage of this solution, which lies in the use of many structural parts, and also the sole plate has to have a special design. The use of many structural parts is not only expensive, also the sources for errors increase and the frictional forces which must be overcome increase. A further disadvantage consists in the structural parts which determine the position of the vertical pivot axis not permitting any play for absorbing tension forces, which are created by a bending or flexing of the ski, for example during skiing over a depression. Furthermore, it is absolutely necessary that the sole plate can pivot also about an additional horizontal axis.
According to Austrian Pat. No. 330,632, which corresponds to U.S. Pat. No. 4,033,603, it is also known to use one single pin or swivel part, wherein the pivot pin permits the sole plate to carry out both a limited pivoting in the horizontal and also in the vertical plane, before a release operation takes place. The pivot pin serves mostly to center and position the sole plate.
It is already known from Austrian Pat. No. 299,030, which corresponds to U.S. Pat. No. 3,797,839, to balance the bend or flex in the ski by rigidly connecting the plate to the ski at a fastening point. However, this design does not permit a swivelling of the sole plate in relationship to the ski, so that a spring-loaded locking mechanism cannot be used, which could control the release operations during a twisting fall and partly during a digonal fall, as this is possible for example in the aforementioned construction according to Austrian Pat. No. 330,632 and is also realized in the case of the subject matter of the invention. The solution according to Austrian Pat. No. 302,130, which corresponds to U.S. Pat. No. 3,797,844, in which the plate is held between two bearing points in a continuous spacing from the upper surface of the ski, can also not be used for a similar reason.
In order to be complete further reference is made to Austrian Pat. No. 326,015, which corresponds to U.S. Pat. No. 3,937,480, in which a plate is held pivotally about a pivot pin and rotatably with respect to a spring-loaded locking mechanism in the downhill skiing position. This known solution does not exceed what has been described in Austrian Pat. No. 330,632 and does not exceed the above-discussed state of the art.
The goal of the invention is to avoid the mentioned and further disadvantages of known constructions and to provide a sole plate of the abovementioned type as insensitive as possible to a bending or flexing of the ski.
The set purpose is inventively attained by the pivot pin being constructed as a telescoping pin having an annular flange, which flange is positioned through a sleeve in a recess of the sole plate, which recess is open on top and limits its vertical movement. Through the inventive construction of the pivot pin as a telescopic structural part and of the recess it is possible to absorb a considerably greater amount of bending or flexing of the ski than has been possible, without causing the ski boot to jam in the ski binding, since the sole plate behaves during a bending of the same like a chord with respect to an arc.
Further details, advantages and characteristics of the invention will be described more in detail with reference to the drawings, which illustrate two exemplary embodiments.